code: def _debug_plot(self, img_data, roi_data):
      color = (0, 255, 0)
      thickness = 2
      for rect in roi_data:
          pt1 = tuple([int(float(x)) for x in rect[0:2]])
          pt2 = tuple([int(float(x)) for x in rect[2:4]])
          try:
              cv2.rectangle(img_data, pt1, pt2, color, thickness)
          except:
              print("Unexpected error:", sys.exc_info()[0])
  
      mp.imshow(img_data)
      mp.plot()
      mp.show()
  
file_path: CNTK/Examples/Image/Detection/utils/od_reader.py
imports: import zipfile
  import cv2
  import numpy
  import os
  from utils.proposal_helpers import ProposalProvider, compute_targets, compute_image_stats
label_desc: Use image node_id 4 for calling the ObjectDetectionReader obj's underlying member method code with example usage: obj._debug_plot(img_data, roi_data) without return types